Modeling Dynamic Soil Properties in Soil Survey.

Historically, soil survey products described inherent soil properties for an entire soil profile under common land use. The National Cooperative Soil Survey (NCSS) recognized the need to provide enhanced information about soil change in response to land use, management or climate changes. New projects are being started to collect and aggregate dynamic soil properties (DSPs). These projects focus on surface layers that respond most rapidly to changes in management or land use. While changes in DSPs are best measured over time through long-term studies and monitoring, changes in DSPs can be estimated using soil survey methods by careful space-for-time substitution comparing land use or management conditions (i.e. vegetation, tillage, climate) on the same soil. In order to provide comprehensive information about a range of soil and management conditions, soil survey projects must be supplemented using predictive models. A combination of modeling and data collection will allow soil survey to quickly populate a DSPs database and inform conservation tools. APEX, a comprehensive model (weather, hydrology, soil erosion-sedimentation, plant growth, nutrient cycling, soil temperature, soil moisture, tillage, and plant environment control) will be evaluated for use in populating DSPs for soil survey. Soil survey DSPs can be used in conservation tools to assist land managers in their evaluations of likely management impacts on soil properties. Of particular interest is the rate of change and resilience of soils disturbed by cultivation.